| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress deterioration of purification catalyst to secure stable exhaust purification performance, and to improve output performance and fuel economy, in an internal combustion engine. <P>SOLUTION: Cylinder groups are arranged to the right and left as first and second banks 12 and 13. Exhaust pipes 57, 58 are connected to each cylinder group of the banks 12 and 13. Front stage three-way catalysts 59, 60 and control valves 64, 65 are respectively provided in the exhaust pipes 57, 58, their upstream portions are connected by a communicating pipe 63, and a turbocharger 67 is installed at a first bank 12 side. A bypass pipe 72 bypassing a second front stage three-way catalyst 60 is provided in a second exhaust pipe 58 with no turbocharger 67, the bypass pipe 72 is provided with a third control valve 73, and each of the control valves 64, 65, 73 are controlled to be opened or closed depending on engine operational status by an ECU 81. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
